Hikari's goal was simple: **refine her body into a weapon**.
By merging the **Byakugan's** perception with the **Shikotsumyaku's** bone manipulation, she'd unlocked an ability she called *"Absolute Physique Control"*—a power that defied human biological limits. Now, armed with fragmented knowledge from her past life (and a *lot* of trial-and-error), she aimed to forge a vessel worthy of battle.
In the shinobi world, combat styles fell into three categories:
1. **Taijutsu** (Physical Combat)
2. **Ninjutsu** (Chakra Techniques)
3. **Genjutsu** (Illusions)
The **Kaguya** and **Hyūga** clans rarely relied on ninjutsu. Hikari's own arsenal was pitiful—**basic Academy techniques** and her bone-based kekkei genkai. Even in *Naruto's* world, only **Rock Lee** had a worse ninjutsu portfolio.
But **taijutsu**?
That was where her bloodlines *shined*.
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Taijutsu relied on **chakra-enhanced muscles**—flooding tissue with energy to amplify strength, speed, and durability. The more chakra and muscle mass a shinobi had, the greater their power.
Hikari's plan? **Optimize both.**
In Kirigakure, she'd hesitated—too many eyes, too much risk. But now, free under Ritsuki Mari's trust, her experiments could begin.
Her first innovation: **subdermal bone armor**.
Already, her **eyeballs** were shielded by a stone-like **bone film** (which had fooled the ANBU). That same membrane now coated her *entire body*—beneath a deceptively soft layer of fat, her skin hid **interlocking skeletal plates**. Her abdomen? Reinforced with **crossed ribs**.
For a normal human, this would mean paralysis. But the **Shikotsumyaku** laughed at biology. Her bones could be **steel-hard** or **paper-flexible** at will.
*And that was just the foundation.*
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Hikari's "perfect" body needed four traits:
1. **Attack Power**
2. **Defense**
3. **Speed**
4. **Range**
Bones handled **defense** (armor) and **range** (extendable weapons). That left **attack** and **speed**—specifically, **muscle efficiency**.
Most assumed *bigger muscles = stronger hits*. A naive view. True strength depended on:
- **Muscle Fiber Density** (More contractile fibers, less inert "filler" tissue)
- **Optimal Fiber Length** (Like a rubber band—too loose or taut weakens force)
- **Leverage Angles** (Physics mattered; a poorly placed tendon wasted energy)
- **Fiber-Type Ratio** (Fast-twitch *"white fibers"* for power vs. slow-twitch *"red fibers"* for endurance)
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Lying in her tent, Hikari **rewrote her flesh**.
Chakra surged from her heart, saturating her right arm's muscles. Under the **Byakugan's** precision, fibers **snapped**, **lengthened**, and **reknit**—thicker, tougher. She **suppressed useless "filler" tissue**, forcing pure, chakra-fed contractile power.
*Snap. Crack. Hiss.*
Her arm **bulged subtly**, its weight tripling. Yet outwardly? Still a girl's slender limb—**pale, unmarred, deceptively delicate**.
She flexed.
*Whoosh—*
The air *rippled*. A single motion sent gusts tearing through the tent.
**Result:**
- **Outer Layer:** Soft skin (disguise)
- **Middle:** Bone armor (slash resistance)
- **Inner Muscle:** Ultra-dense fibers (blunt-force cushioning)
- **Core:** Titanium-grade bones (structural integrity)
*…Wait.*
She'd aimed for offense but accidentally maxed out **defense**. *Typical.*
Now, her right arm could **punch through stone** yet weighed like a boulder. Mobility would suffer if she scaled this up.
*Time to recalibrate.*
Comparing her asymmetrical arms, Hikari pondered:
*"The golden ratio… Where's the balance between speed, power, and mass?"*
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Outside, her team kept watch:
- **Mari** (setting perimeter traps)
- **Shin** (napping in a tree for night shift)
- **Karin** (leaning against Hikari's tent, half-asleep)
- **Yōma** (perched high, scanning for threats)
*"Worth every ryō,"* Hikari mused, grateful for their vigilance.
As the firelight flickered, she resumed her work—sculpting herself into something *beyond human*.
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